Abstract
The aim of our study was to compare the clinical versus radiological diagnosis of patients suffering from a Morton's neuroma. Clinical assessments and pre operative radiological imaging of patients who underwent operative procedures for an excision of a Morton's neuroma were retrospectively compared. This review included 43 excised Morton's neuromas from 36 different patients over a period of 68 months, performed by one surgical team.
The commonest clinical symptoms were those of pain or tingling on the plantar aspect of the affected webspace on direct palpation (100%), pain of weight bearing (91%) which was relieved by rest (81%) and pain on stretching the toes (79%). The most sensitive clinical sign was a Mulder's click.
Our results showed that clinical assessment was the most sensitive method of diagnosing these neuromas (98%). All of our patients had at least one mode of radiological investigation. Ultrasonography was the commonest requested single imaging modality in our series. It was found to have a sensitivity of 90% (28/31). This imaging technique has the disadvantage of being operator dependant, as highlighted by the fact that one of our patients had a correct radiological diagnosis after a repeat ultrasound to the affected area was requested. Magnetic Resonance Image scan is a more expensive technique as it has the advantage of producing static reproducible images. As a single imaging modality, it was found to have a sensitivity of 92% (12/13) in our series. 3 patients had both imaging modalities; initial ultrasound failed to convincingly diagnose a neuroma in 2 cases and in the other case, the initial MRI did not show any pathology. In all these cases, the repeat imaging techniques confirmed the clinical diagnosis.
We conclude that there is no absolute requirement for ultrasonography or magnetic resonance imaging in patients who clinically are suspected to have a Morton's neuroma, as the clinical examination was found to be the most sensitive method of diagnosis. We suggest that the two main indications for performing some form of imaging is (a) an unclear clinical assessment and (b) cases when more than one webspace appears to be affected. An ultrasound of the webspaces should be the radiological investigation of choice, followed by a magnetic resonance scanning if any uncertainty still remains.
